I am trying to get the "Combat Engineer" ribbon in Horde 2.0 mode of Gears of War 3. The gears wiki says
Combat Engineer: Build, repair, and or upgrade 5 fortifications during wave-half time.
I am playing gears by myself and have purchased 5 different items in between waves numerous time but I never seem to get this ribbon (I have received it once but don't remember when). Does it only count if I buy barriers? Or can I buy decoys and turrets as well? Do I have to be playing co-op with someone else or can I get the ribbon while playing by myself? Does it matter which map I use? Just general help on what I am doing wrong would be appreciated.